Chapter 14 – SIM Toolkit
Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 139
Messages Exchanged During a SIM Toolkit Operation
The following scheme shows the SIM Toolkit commands and unsolicited results that are exchanged.
Step 1:
The customer application informs the modem which facilities are supported. This operation is performed with the +STSF
(SIM Toolkit Set Facilities) command, which also activates or deactivates the SIM Toolkit functionality.
Step 2:
An unsolicited result +STIN (SIM Toolkit indication) is sent by the product in order to indicate to the customer application
which command type the SIM Application Toolkit is running. The last SIM Toolkit indication can be requested by the
+STIN? command.
Step 3:
The customer application uses the +STGI (SIM Toolkit Get Information) command to get all the information about the SIM
Toolkit command, given by +STIN.
Step 4:
The customer application uses the +STGR (SIM Toolkit Give Response) to send its response (if any) to the SIM Toolkit
Application.
The +STCR (SIM Toolkit Control response) indication is an unsolicited result sent by the SIM when Call control
functionality is activated and before the customer application has performed any outgoing call, SMS, SS, or USSD.
MULTI-TECH
Modem
Customer
Application
+STSF=X,XXXXXXXX
+STIN=X
+STGI=X
+STGI response
+STGR=X,XXXXXX
STEP 1: Configuration and Activation
STEP 2: SIM sends pro-active command
STEP 3: Customer application gets all the information.
STEP 4: User response is sent to the SIM.
+STCR:X